Posted by **Priscilla** on Friday, December 25, 2009 at 10:43pm.

A race car can be slowed with a constant acceleration of -11 m/s^2

a. If the car is going 55 m/s, how many meters will it travel before it stops?

b. How many meters will it take to stop a car going twice as fast?

- Physics -
**Damon**, Saturday, December 26, 2009 at 4:18am
v = Vo + a t

so

v = 55 - 11 t

when is v = 0 ?

0 = 55 - 11 t

so t = 5 seconds to stop

d = Vo t + (1/2) a t^2

d = 55 (5) - (1/2) 11 (25)

= 275 - 137.5

=137.5 meters

Now do that again for Vo = 110 m/s

- Physics -
**Heart**, Saturday, December 26, 2009 at 8:49am
Ok, thanks but i dont understand b. I know you use the equation d = Vit +1/2 at^2 but to find the distance would you just calculate d = vit only.

- Physics -
**Damon**, Saturday, December 26, 2009 at 2:03pm
No, do v = Vo + a t again with

0 = 110 - 11 t

then use that t in

d = 110 t - (1/2)11 t^2

## Answer This Question

## Related Questions

- physics - A race car can be slowed with a constant acceleration of -14 m/s2. (a...
- Physics - A race car can be slowed with a constant acceleration of -11 m/s^2 a...
- Physics - A race car can be slowed with a constant acceleration of -11 m/s^2 a. ...
- physics - a race car can be slowed with a constant acceleration of -11m/s2. a.if...
- Physics - A race car can be slowed with a constant acceleration of -11 m/s^2 a. ...
- Physics - A car is going 18.3 m/s down a road. At time t=0s, a squirrel runs in ...
- physics with 6 questions - Two cars start from rest at a red stop light. When ...
- physics - Two cars start from rest at a red stop light. When the light turns ...
- physics - You are driving a car 35mi/h down the road. The stoplight in front of ...
- Physics - Two cars start from rest at a red stop light. When the light turns ...

More Related Questions